In a low‑bleeding‑risk adult who received a second‑generation drug‑eluting coronary stent and has completed the required period of dual antiplatelet therapy, what is the earliest time after stent placement that aspirin can be discontinued?

Aspirin Can Be Discontinued as Early as 1 Month After Second-Generation Drug-Eluting Stent Placement

In low-bleeding-risk adults who received a second-generation drug-eluting coronary stent, aspirin can be discontinued as early as 1-3 months after stent placement, with continuation of P2Y12 inhibitor monotherapy. This strategy reduces bleeding risk without increasing ischemic events or stent thrombosis 1, 2.

Evidence-Based Timeline

The most recent ACC/AHA/SCAI guidelines (2022) provide a Class 2a recommendation (Level A evidence) that shorter-duration DAPT of 1-3 months is reasonable with subsequent transition to P2Y12 inhibitor monotherapy to reduce bleeding events 1. This represents a paradigm shift from traditional aspirin-based long-term therapy.

The 2024 ESC guidelines further support this approach, stating that stopping DAPT after 1-3 months from PCI-stenting may be considered in patients who are not at high bleeding risk nor at high risk of ischemic events 2. Importantly, after this initial period, patients should continue with either:

• P2Y12 inhibitor monotherapy (preferred), OR
• Aspirin monotherapy if P2Y12 inhibitors are contraindicated

Key Clinical Algorithm

For patients with stable ischemic heart disease (SIHD) after second-generation DES:

1. Months 0-1: Mandatory DAPT (aspirin + P2Y12 inhibitor)
2. Months 1-3: Consider discontinuing aspirin if:
   • Low bleeding risk profile
   • Second-generation DES used
   • No high-risk features for stent thrombosis
   • Continue P2Y12 inhibitor monotherapy
3. Beyond 3 months: P2Y12 inhibitor monotherapy continues

For patients with acute coronary syndrome:

• Minimum 6 months DAPT recommended as default 2
• May consider 1-3 month DAPT in very high bleeding risk scenarios

Supporting Evidence Quality

Multiple high-quality randomized trials support early aspirin discontinuation. A meta-analysis of five RCTs (n=18,357) demonstrated that short-term DAPT (≤3 months) followed by P2Y12 monotherapy significantly reduced major bleeding (OR=0.43) and any bleeding (OR=0.56) without increasing all-cause death, major adverse cardiac events, or stent thrombosis 3.

The SECURITY trial specifically tested 6 versus 12 months DAPT after second-generation DES and confirmed non-inferiority, with definite/probable stent thrombosis rates of only 0.3% versus 0.4% at 12 months 4. OCT imaging studies further validate that interrupting DAPT at 9 months does not affect neointimal proliferation or stent strut coverage 5.

Critical Caveats

Do NOT discontinue aspirin early if:

• First-generation DES was used (requires longer DAPT)
• High ischemic risk features present (complex lesions, left main disease, bifurcation stenting)
• Patient has concurrent indication for oral anticoagulation (different algorithm applies)
• Very high bleeding risk requiring 1-month DAPT (Class IIb recommendation) 2

Absolute earliest discontinuation: While 1 month is mentioned in guidelines for very high bleeding risk patients, the safest evidence-based minimum is 3 months for routine practice in low-bleeding-risk patients 1, 3, 4.

Practical Implementation

The transition strategy involves:

• Stopping aspirin at 1-3 months
• Continuing clopidogrel 75 mg daily indefinitely (or ticagrelor/prasugrel if used for ACS)
• This P2Y12 monotherapy provides equivalent ischemic protection with significantly less bleeding than continued DAPT

This approach specifically applies to second-generation DES (everolimus, zotarolimus-eluting stents), which have substantially lower thrombogenicity than first-generation devices 6, 7.